Demography: births, migration and age structure

German statistics has a picture where English has a noun. When two curves on a chart start close together and drift apart, English says the gap is widening; German says die Schere geht auseinander, the scissors are opening, and sees the two lines as blades hinged at the point where they last met. The image travels well beyond this list — die Schere zwischen Arm und Reich is a newspaper staple — but demography is where it is most at home, because births and deaths make exactly such a pair: der Sterbeüberschuss is simply the width between the blades. The picture runs in both directions. Die Schere schließt sich when the lines converge again, and a sentence can say how far the scissors are open without quoting a single figure. In a report, read the idiom as a statement about a trend, not about a level.